A plate member conveying apparatus is configured in accordance with the characteristics of a plate member to be conveyed. For example, in a machining line of plate glass (plate member) used for a TFT (thin film transistor) liquid crystal display, a conveying apparatus capable of conveying the plate glass without contacting one of surfaces of the plate glass is required. This is because since a thin film layer, such as a semiconductor, are formed on one of surfaces of the plate glass for the liquid crystal display, the formations of even minor scratches on this surface are unacceptable. Hereinafter, such a surface to be subjected to precision machining is called a “precision surface”.
As the conveying apparatus configured to convey the plate glass without contacting the precision surface, an apparatus configured to cause a wagon to move in a conveying direction in a state where a surface (hereinafter referred to as a “normal surface”) opposite to the precision surface of the plate glass is being sucked by a sucker provided at the wagon has already been put to practical use. However, in the case of this conveying apparatus, every time the plate glass is conveyed, the wagon needs to be returned to an initial position, so that it is difficult to efficiently operate this conveying apparatus. Also proposed are an apparatus configured to convey the plate glass in a state where the plate glass is mounted on a belt conveyor, and the normal surface faces downward, that is, the plate glass is in a horizontal state and an apparatus configured to convey the plate glass in a state where the plate glass is mounted on a belt conveyor, and the plate glass is in a standing state (see PTL 1, for example).